Needle plate latch



Oct. 8, 1957 w. A. AYRES NEEDLE PLATE LATCH Filed Jan. 19, 1955 r f J #W fr New nited Sttes Patent j() NEEDLE PLATE LATCH Waldemar A. Ayres, Lakewood, Ohio, assignor to White Sewing Machine Corporation, Lakewood, Ohio, a corporation of Delaware Application January 19, 1955, Serial No. 482,700

Claims. (Cl. 112-260) The present invention relates to sewing machines and, more particularly, to the construction of the cover plate and its supporting and latching mechanism for a hand hole in the bed plate of a sewing machine.

An object of the present invention is the provision of a new and improved lspring pressed latching mechanism which, in combination with suitable stop means, automatically positions and securely holds a removable cover plate in a hand hole opening in the bed plate of a sewing machine when the latching mechanism is permitted to engage one side edge of the cover plate and force its opposite side into engagement with the stop means, thereby confining the cover plate therebetween, and which latching mechanism automatically raises the cover plate out of the hand hole when moved to an open position.

A further object of the invention is the provision of a new and improved bed plate for a sewing machine having a hand hole opening therein directly below the needle bar of the machine and which bed plate is provided with a spring pressed latching mechanism adapted to engage one side edge of a removable needle plate and force the needle plate, when the latching mechanism is released, into engagement with suitable needle plate stop means, which automatically aligns openings in the needle plate accurately with respect to the needle and feed dog mechanisms of the machine.

An additional object of the invention is the provision of a new and improved sewing machine bed plate of the type described above in which the stop means for the needle plate is adjustably clamped relative to the bed plate of the machine to facilitate manufacture .and to permit correct and accurate alignment of the needle hole in the needle plate relative to the path of the needle to be more easily attained during the assembly of the sewing machine.

Another object of the invention is the provision of a new and improved sewing machine having a bed plate with a hand hole opening therein directly below the needle bar of the machine, which opening is adapted to be closed by a needle plate having suitable openings therein adapted to receive the needle and feed dog mechanisms of the sewing machine and which needle plate is adapted to be accurately positioned and held relative to said needle and feed dog mechanisms by suitable means comprising, needle plate stop means positioned adjacent one side of the hand hole and spring biased latch means positioned adjacent the opposite side of the hand hole, said latch means comprising a normally vertically extending latch member whose lower end is pivotally mounted to the bed about an axis beneath and substantially parallel with the top surface of the bed plate, and whose upper end is provided with a recess adapted to receive one end of the needle plate, and which latch member is spring biased for movement toward said needle plate stop means to force theV needle plate into engagement with the stop means and securely hold the needle plate therebetween.

Further and additional objects and advantages not hereinbefore referred to will become apparent during the detail description of an embodiment of the invention Z which is to follow. Referring to the drawing illustrating said embodiment of the invention and forming part of this specification:

Fig. 1 is a fragmentary plan view of the bed plate of a sewing machine showing a rectangularly shaped hand hole opening therein which is closed by a removable needle plate and its supporting and latching structure in accordance with the principles of the present invention;

Fig. 2 is a fragmentary sectional view takenrapproximately on the line 2 2 of Fig. 1 and in which dot-dash lines are used to show the open position of the latching mechanism in which one end of the needle plate is supported out of the hand hole opening;

Fig. 3 is a side elevational view of the structure shown in Fig. 1 showing the open position of the latching mechanism by means of dot-dash lines;

Fig. 4 is an enlarged fragmentary side view of the left hand portion of the structure shown in Fig. 3, and

Fig. 5 is an enlarged fragmentary view showing thev latching mechanism held against its stops with the needle plate resting on top of the latching mechanism preparatory to the latch being rotated counterclockwise to receive the end of the needle plate.

Referring to the drawings, the bed or work plate of a sewing machine is generally indicated as 10 and is provided with a rectangularly shaped hand hole opening 11 whose length is positioned lengthwise of the bed. 'The opening 11 is positioned directly above the rotary hook mechanism (not shown) located in the bed of the sewing machine, which mechanism is adapted to cooperate with the eye portion of a needle which is reciprocated from' a position below the bed plate and adjacent to the rotary hook mechanism to a position labove the bed plate 10 by a reciprocating needle har (not shown) in a manner well known in the art. Surrounding the path of the needle and also located in the bed of the machine is the feed dog mechanism (not shown) of the machine which is adapted to be moved upwardly of the bed plate 10 periodically to engage the under surface of material being sewn by the machine and advance the material crosswise of the rectangularly shaped opening 11 in a manner well known in the art. y. Y n

The rectangularly shaped opening 11 is closed by suit able structure which lies flush with the top surface of the bed plate to provide a at continuous supporting surface for the material being sewn and which structure includes a removable section or needle plate A. The needle plate A is provided with a centrally located and slightly elongated needle hole 12 through which the eye portion of the needle is reciprocated by the needle bar of the sewing machine and surrounding which are rectangularly shaped openings 13 which extend crosswise of the needle plate A and which receive the previously referred to feedkdog mechanisms. The needle plate A of the present instance is made removable to provide ready access to the rotary hook and bobbin mechanisms positioned beneath the needle plate A and it is imperative that the needle plate be capable of being placed into position quickly and accu-` rately with the needle hole 12 and feed dog openings 13 correctly aligned with respect to the path of the needle and the feed dog mechanisms respectively of the machine.

The needle plate A is accurately positioned crosswise of the rectangularly shaped opening 11 by thefront and back side edges of the needle plate which engage the front and back side edges respectively of the opening 11, as viewed in Fig. l. The needle plate A is accurately positioned lengthwise of the rectangularly shaped opening 11 by means of a stop plate B positioned in the right hand end of the opening 11, as viewed in the drawings, and which contains a recess 14 in its top surface into which the right hand end of the needle plate A is adapted to rest. The stop plate B extends across the full Width` of the opening 11 and is adjustably bolted to the support;

Patented Oct. 8, 1957V 3 ing members D of the bed by means of two ilister head machine screws 16 seated in oversized receiving holes 17 in the` stop plate B. Oncelthe needle plate A is accurately positioned relative to the path' of the needle Aand to the feed do"g"mechanism s`, the stop plate'B' is-'adjusted' until the.. generally vertically inclined or rabb'eted side edge 18 of its recess 14 abuts the complementally shaped endofthe needle plate A, in whichrposition the machine screws 16 are tightened to thereafter provide a stationary stop surface against which the right hand edge of the needle -plate A- may be positioned. Alternatively, where the adjustable'` feature of the stop plate is not desired, the stop plate'B may be` permanently fixed to or may be vmade an integral part of the bed plate structure of the sewing machine.YH -j Y i The' opposite or lefthandend of the Ane'edleplate A is 'adapted to be supported by two vertically extending members or posts'Zt)` and21- formingpart ofthe bedy and positioned adjacent'opposite sides. of the opening 11 and between which a generally T-shaped latching mechanism C is supported.A The top surfaces of the posts 20 and 21 are flush withV the top surface of the bed plate and each is provided 'with a recess 22 along their top right'hand edges adapted toreceive the respectivefront and back left hand corners of the needle plate A and support the left hand side of the needle plate flush with the top sur face of the bed plate.

It will now be apparent that the needle plate A will be supported ush with the top surface of the bed plate 10 when the right and lefthand ends of the needle plate are positioned in the recess 14 of the stop plate B, and the recesses 22 of the posts 20 and 21 respectively; and that the needle hole 12 and feed dog openings 13 will be accu rately positioned relative to mechanisms which they receive when the right hand vertically inclined or rabbeted edge of the needle plate A abuts the generally vertically inclined or rabbeted side edge 1S of the recess 14 in the stop plate B. The needle plate A is adapted to be held in this position by the latching mechanism C previously mentioned and which will now be described in detail.

The latching mechanism C shown in the drawing comprises a generally T-shaped structure 3u whose upper surface is adapted, when in a horizontal position, to close off the remaining portion of the rectangularly shaped opening 11, and the right hand portion of whichfis recessed, as at 31, to extend under and receive the portion of the needle plate A which extends between the posts 2t) and 21. The lower end of the T-shaped structure 3U is pivotally mounted about a horizontal stationary shaft 32 whose ends are supported in holes 33 and 34 in theV lower ends of the posts and 21 respectively which extend upwardly from the support structure D for the driving mechanism of the operative parts in the bed of the sewing machine. The ends of the shaft'32 are held in the holes 33 and 34 by setscrews 35 and 36 positioned in the posts 20 and 21 respectively, and the latching mechanism is spring pressed or biased for movement toward the stop plate B by a spring blade 37 one end of which bears against the left side of the T-shaped latch structure above the shaft 32 and the other end of which is lixed to the support structure D as by a screw 38 positioned directly below the latching mechanism. The T-shaped latch structure is prevented from being rotated by the spring 37 beyond the stopped position shown in Fig. 5 of the drawing, which position is slightly tothe right of the T-shaped structures Vertical position, by front andrear side portions of its left hand top horizontal section which extend in behind the posts 20 and 21 and abut therewith to prevent clockwise rotation beyond Vthe stopped position. The iight hand horizontal portion of the T-shaped structure which underlies the needle plate A has its center section removed, or notched out, so as not to interfere with the circular window 40 and its supporting structure located thereabove inthe needle plate A. Suicient clearance is provided adjacent'v the left hand edge of the rectangularly shaped opening 11 and the T-shaped structure 30 to permit the structure to be rotated counterclockwise against the action of the spring to open positions corresponding to those indicated by the dot-dash lines in Figs. 2, 3, and 4 of the drawing wherein the right hand edge of the T-shaped structure 30 is tilted above the top surface of the bed plate 1i) and the left hand edge is moved beneath the bed plate.

The needle plate A is installed in the hand hole opening between the stop plate B and latching mechanism C by depressing the left hand side of the latching mechanism C to swing the mechanism to its open position; laying the needle plate A above the hand hole opening with its right hand edge resting-in the recess 14 of the stop plate B and the left hand end of the needle plate A resting on the elevated right hand 'edge of the latching mechanism C as shown by the dot-dash lines in Fig. 2; and thereafter slowly releasing the latching mechanism.

The generally vertically inclined or rabbeted sides or abutment edges 18 and 41 of the recesses 14 and 31 in the stop plate B and latching mechanism C, respectively, are made to slope inwardly in the present instance, to undercut the top surfaces of their respective parts and more firmly interlock with the needle plate A whose cooperating edges are correspondingly beveled. As the latching mechanism C is released, the top surface of the T-shapedv latching structure is rotated clockwise into a horizontal position lowering its right hand edge and the left hand end of the needle plate A resting thereon. Inst. before the top surface of the T-shaped latching structure reaches its horizontal position, the needle plate A is lowered suiiciently so that its lower left hand edge just drops below plate B, thereby accurately positioning the needle plate and locking the same in place.

Removal of the needle plate A is accomplished by depressing the left hand side of the latching mechanism C, causing it to rotate counterclockwise about the shaft 32. The initial movement of the latching mechanism moves the abutment surface 41 of its recess 31 of the latching mechanism C out of engagement with the left hand edge of the needle plate A and moves the bottom of the recess into engagement with the bottom of the needle plate. Continued rotation of the latching mechanism C causes the right hand edge of the T-shaped latching structure 30 to be rotated above the surface of the bed plate while at the same time moving the abutment surface 41 of its recess back away from the end of the needle plate. The movement of the abutment surface 41 and the right hand edge 'of the T-shaped structure 30 is such that the beveled edge of theV needle plate rides up out of the undercut portion of the recess 31 as the right hand edge of the T- shaped structure lifts the end of the needle plate out of the hand hole opening to a position where an operator can insert his nger underneath the left hand edge of the needle plate and remove the needle plate from the handV hole opening.

While the preferred embodiment of the invention has been described in considerable detail, I do not Wish to be limited to the particular construction shown which may be varied within the scope of the invention, and it is the intention to cover hereby all adaptations, modifications and arrangements thereof which come within the scope of the appended claims.

HavingY thus described my invention, I claim:

l. In a sewing machine wherein the needle bar of the machine reciprocates the eye portion of the needle clamped thereto between positions above and below the plane of the bed plate of the bedV of themachine, a bed plate havingha rectangularlyfshaped openingxtherein di-44 rectly below the needle bar, an adjustment plate positioned in one end of said opening and having its top surface ush with the top surface of the bed plate, means for adjustably clamping said adjustment plate to said bed, said adjustment plate having a recess in its top surface along oneend of the remaining portion of said rectangularly shaped opening, latch means positioned in the opposite end of said opening with its top surface ilush with the top surface of said bed plate, means pivotally connecting said latch means to said bed beneath the plane of the top surface of the bed plate and about an axis substantially parallel with the plane of the top surface of the bed plate, said latch means having a recess in its top surface along its side facing said other recess, a removable needle plate for said opening adapted to close the remaining portion of said opening and lie substantially flush with the upper surface of said bed plate when the opposite ends of said needle plate are positioned in said recesses, said recesses having the side surfaces which face each other and against which the opposite ends of the needle plate abut suitably sloped to undercut the topl surface of the adjustment plate and latch means respectively, said opposite ends of said needle plate being suitably beveled to correspond therewith, and spring means biasing said latch means toward said one end of said hand hole.

2. In a sewing machine wherein the needle bar of the machine reciprocates the eye portion of the needle clamped thereto between positions above and below the plane of the bed plate of the bed of the machine, a bed plate having a rectangularly shaped hand hole therein directly below the needle bar, an adjustment plate positioned in one end of said opening and having its top surface iush with the top surface of the bed plate, means for adjustably clamping said adjustment plate to said bed, said adjustment plate having a recess in its top surface along one end of the remaining portion of said rectangularly shaped opening, latch means having a generally T- shaped cross section positioned in the opposite end of said opening with the top horizontal surface of the T-section flush with the top surface of the bed plate, means pivotally connecting the lower end of the vertical portion of said latch means to said bed beneath the plane of the top surface of the bed plate and about an axis substantially parallel with the plane of the top surface of the bed plate, said latch means having a recess in its top surface along its side facing said other recess, a removable needle plate for said opening adapted to close the remaining portion of said opening and lie substantially ush with the upper surface of said bed plate when the opposite ends of said o needle plate are positioned in said recesses, said recesses having the side surfaces which face each other and against which the opposite ends of the needle plate abut suitably sloped to undercut the top surface of the adjustment plate and latch means respectively, the opposite ends of said needle plate being suitably beveled to correspond therewith, and spring means biasing said latch means towards said one end of said hand pole.

3. In a sewing machine having a bed mounting a bed or work plate provided with a hand hole opening located to underlie the reciprocating needle bar that is above said plate and overlie the feeding and sewing mechanisms that are in the bed below said plate, a rabbeted supporting ledge at one end of said hand hole opening, a latch mechanism having a depending leg the lower end of which is pivotally connected to the bed below the plane of said bed or work plate and on an axis parallel to said plane and extending transversely of the bed, the upper end of said leg being provided with a rabbeted supporting ledge located at the other end of said opening and with a planular surface portion which partially fills said opening and the upper surface of which is ilush with the plane of the upper surface of the bed or work plate when said leg is vertically disposed, spring means carried by said bed and acting on said leg to normally maintain the same vertically disposed, and a removable needle and feed dog plate having its opposite ends supported by and shaped to have a locking intert with said rabbeted supporting ledges when said latch mechanism is in vertical position and with the upper surface of said needle and feed dog plate flush with the upper surface of said bed or work plate and with said planular surface portion of said latch mechanism, said supporting ledge of said latch mechanism forcing the remote end of said needle and feed dog plate into tight interlocked engagement with said other rabbeted supporting ledge, said planular surface portion of said latch mechanism functioning as a latch operating means when downward pressure is applied thereto to swing said latch mechanism about its pivotal axis against the action of said spring means and incline said surface portion downwardly into said opening while said rabbeted supporting ledge of said latch mechanism functions when said latch mechanism is thus swung to raise the adjacent end of said needle and feed dog plate whereby its remote end can be manually withdrawn from its locking intert with said other rabbeted supporting ledge and the needle and feed dog plate can be removed from the hand hole opening.

4. A sewing machine as defined in claim 3 and Wherein said rabbeted supporting ledge of said latch mechanism is provided on its inner edge withA projecting arms spaced apart transversely of the bed and extending beneath the needle and feed dog plate and acting to raise the latter when said latch mechanism is swung by downward pressure applied to said planular surface portion.

5. A sewing machine as defined in claim 3 and Wherein said rabbeted supporting ledge at one end of said hand hole opening is formed on a member separate from said bed or work plate and having a surface portion provided with an opening elongated in the longitudinal direction of the bed, and a securing screw extending through said opening and into said bed whereby said member can be adjusted longitudinally of the bed and relative to the supporting ledge on said latch mechanism and secured in adjusted position.

FOREIGN PATENTS France Feb. 6, 1952 

